Water hyacinths (Eichhornia crassipes) are a free-floating or rooted in mud plant or weed which can completely cover fresh water lakes, harbors, sloughs, and other essentially relatively occluded fresh water bodies. These plants produce in excess of 250,000 pounds of biomass per acre. Further, under optimum growing conditions, the surface area covered by such plants doubles every 10 days. As the densities and growth rate of the plant are so high, mechanical methods of plant removal have not been economically successful.
The leaves of the water hyacinth are large and broadly lance-like, extending from a generally inflated stalk. The flowers are blue, violet or white. The roots are dark and fibrous. Leaf blades may be up to 8 inches long and 2-6 inches wide. The plant reproduces either by seed or fragmentation. It is common in the tropical and subtropical fresh water bodies of the world--and in California, Florida, Texas and the Gulf Coast region of the United States.
Where removal has been undertaken, harvesting barges have contained the harvested plant. When filled with harvested plant, the harvesting barges commute to shore, unload, and return to the harvest site. This results in harvest interruption and transit time loss. As the harvesting barges and their associated crews are relatively high in hourly cost, mechanical harvesting has generally not been economical.
Chemical controls have been tried. Unfortunately, these techniques have undesirable side effects with their toxins. This being the case, chemical control comes under increasing scrutiny with limited use.
An economical system for removal of the hyacinths remains to be disclosed.